[PATCH 1/4] Cleanups to FreeBSD/mips native register operations.
Luis Machado
lgustavo@codesourcery.com
Thu Apr 13 15:48:00 GMT 2017
On 04/12/2017 01:37 PM, John Baldwin wrote:
> Compare against the "raw" PC register number instead of the cooked
> register number when determining if a register was handled by
> PT_GETREGS. Previously the register fetch/store operations only tried
> PT_GETREGS to fetch any individual register. The result was that
> fetching or storing an individual register not covered by PT_GETREGS
> (such as floating point registers) did not work.
>
> While here, remove an early exit to simplify the code flow from the
> PT_GETREGS / PT_SETREGS case, and add a getfpregs_supplies similar to
> getregs_supplies to describe the registers supplied by PT_GETFPREGS
> and PT_SETFPREGS.
>
> gdb/ChangeLog:
>
> * mips-fbsd-nat.c (getregs_supplies): Fix upper bound comparison.
> (getpfpregs_supplies): New function.
> (mips_fbsd_fetch_inferior_registers): Remove early exit and use
> getfpregs_supplies.
> (mips_fbsd_store_inferior_registers): Likewise.
> ---
> gdb/ChangeLog | 8 ++++++++
> gdb/mips-fbsd-nat.c | 26 ++++++++++++++------------
> 2 files changed, 22 insertions(+), 12 deletions(-)
Only a few nits.
> diff --git a/gdb/mips-fbsd-nat.c b/gdb/mips-fbsd-nat.c
> index 078df52db6..e2ed63e829 100644
> --- a/gdb/mips-fbsd-nat.c
> +++ b/gdb/mips-fbsd-nat.c
> @@ -37,7 +37,16 @@ static bool
> getregs_supplies (struct gdbarch *gdbarch, int regnum)
> {
> return (regnum >= MIPS_ZERO_REGNUM
> - && regnum <= gdbarch_pc_regnum (gdbarch));
> + && regnum <= mips_regnum (gdbarch)->pc);
> +}
Can the BSD backend override the pc value in gdbarch_pc_regnum (...) so
it fits what is expected? Or is this a case where the cooked pc register
number is still useful and we need to handle things differently for the
raw pc register number?
> +
> +/* Determine if PT_GETFPREGS fetches this register. */
Pedantically, "... fetches REGNUM".
> @@ -47,9 +56,9 @@ static void
> mips_fbsd_fetch_inferior_registers (struct target_ops *ops,
> struct regcache *regcache, int regnum)
> {
> + struct gdbarch *gdbarch = get_regcache_arch (regcache);
> pid_t pid = get_ptrace_pid (regcache_get_ptid (regcache));
>
> - struct gdbarch *gdbarch = get_regcache_arch (regcache);
> if (regnum == -1 || getregs_supplies (gdbarch, regnum))
With C++ we can leave the declaration closer to its use. Same in the
other case below.
> @@ -58,12 +67,9 @@ mips_fbsd_fetch_inferior_registers (struct target_ops *ops,
> perror_with_name (_("Couldn't get registers"));
>
> mips_fbsd_supply_gregs (regcache, regnum, ®s, sizeof (register_t));
> - if (regnum != -1)
> - return;
> }
>
> - if (regnum == -1
> - || regnum >= gdbarch_fp0_regnum (get_regcache_arch (regcache)))
> + if (regnum == -1 || getfpregs_supplies (gdbarch, regnum))
Does MIPS on fsbd handle vector registers? I ask this because regnum >=
"fp0 regnum" may mean anything other than general purpose registers.
If there are vector (or higher-numbered registers), the new conditional
block means something different compared to the old one.
If not, then the change looks sane.
> @@ -82,9 +88,9 @@ static void
> mips_fbsd_store_inferior_registers (struct target_ops *ops,
> struct regcache *regcache, int regnum)
> {
> + struct gdbarch *gdbarch = get_regcache_arch (regcache);
> pid_t pid = get_ptrace_pid (regcache_get_ptid (regcache));
>
> - struct gdbarch *gdbarch = get_regcache_arch (regcache);
> if (regnum == -1 || getregs_supplies (gdbarch, regnum))
> {
> struct reg regs;
Same as above about declaring something closer to where it is used.
> @@ -97,13 +103,9 @@ mips_fbsd_store_inferior_registers (struct target_ops *ops,
>
> if (ptrace (PT_SETREGS, pid, (PTRACE_TYPE_ARG3) ®s, 0) == -1)
> perror_with_name (_("Couldn't write registers"));
> -
> - if (regnum != -1)
> - return;
> }
>
> - if (regnum == -1
> - || regnum >= gdbarch_fp0_regnum (get_regcache_arch (regcache)))
> + if (regnum == -1 || getfpregs_supplies (gdbarch, regnum))
Same thing as above, about higher-numbered registers.
Otherwise i have no further comments.
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